A. Silvacastillo et al., DOUBLE CRITICAL-STATE MODEL FOR THE WEAK-LINK REGIME OF GRANULAR HIGH-T-C SUPERCONDUCTORS, Physica. C, Superconductivity, 296(1-2), 1998, pp. 75-83
The phenomenological double critical-state model, which uses critical
values for the components of the current-density both perpendicular an
d parallel to the local magnetic induction B, is applied to tubes of g
ranular high-T-c superconductors in the presence of axial and azimutha
l magnetic fields. We develop a theory valid for the weak-link regime
of these superconductors. In this theory not only intergranular but al
so intragranular currents are taken into account. The behavior of the
magnetic induction inside the wall of a superconducting tube cooled be
low the critical temperature in the axial magnetic field and, later, s
ubjected to an increasing azimuthal field, is analyzed. Our theoretica
l results are compared with the experiment. (C) 1998 Elsevier Science
B.V.